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Finding the Fourth Proportional to 100.17, 138.15 and 74.25

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Solution

The fourth proportional to 100.17, 138.15 and 74.25 is: 102.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.17 : 138.15 = 74.25 : x
  2. Step 2: Convert to fraction form
    100.17/138.15 = 74.25/x
  3. Step 3: Cross multiply
    100.17x = 138.15 × 74.25
  4. Step 4: Simplify right side
    100.17x = 10,257.64
  5. Step 5: Solve for x
    x = 10,257.64/100.17
  6. Step 6: Final answer
    x = 102.40

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.